The present invention relates to methods for producing an aged or matured tea material and a tea beverage which have an improved flavor and leave a pleasant aftertaste, by treating a tea material for drinking by a specific process.
Tea is a luxury beverage made from young buds and young leaves of tea plants as evergreen shrubberies of Camellia sinensis, and is roughly classified into three types of an unfermented tea, a fermented tea and a semi-fermented tea. These tea materials are classified on the basis of the difference in the production processes, and will be briefly explained below. The unfermented tea is the one obtained by, immediately after plucking leaves, heating the leaves to inactivate enzymes, followed by drying so as to keep the green color and develop the flavor and taste, i.e. the one made by a process not including a fermentation step. Green tea belongs to this group. The fermented tea is the one obtained by rolling or crumpling thoroughly the plucked leaves, and conducting oxidation with oxidases in the leaves, fermentation and drying, i.e. the one made by a process including a fermentation step. Black tea belongs to this group. Further, the semi-fermented tea is the one obtained by stopping the fermentation step on the way in the above production process of the fermented tea, followed by drying for finishing. Chinese teas such as oolong tea belong to this group.
Further, in addition to the above tea material for drinking made from the young buds and young leaves of tea plants, other tea materials for drinking made from plants other than evergreen shrubberies of Camellia sinensis, have been known, for example, barley tea (barley water or ptisan: the one obtained by roasting barley as covered with husks and finishing) and herb tea (the one obtained by drying fragrant grass leaves, stalks, seeds, etc.).
The tea materials for drinking and the tea beverages obtainable from such tea materials for drinking as mentioned above, are liked by people in many countries, and their consumption is substantial. Various processes and machines have been devised to make these tea beverages more tastily. However, the main stream is directed to a process for optimizing the conditions in extracting or steeping water-soluble components from the tea materials for drinking to produce good flavor. However, the flavor of conventional tea materials for drinking depends on the quality of young buds, young leaves, etc. of tea plants as the starting material, and after all, tasty teas tend to be expensive because high quality tea materials are used. For example, it is commonly known that Shincha (the first tea of the season or newly picked tea) is better than Bancha (coarse tea) in flavor, but the Shincha is substantially expensive as compared with the Bancha.
Further, in recent years, many types of canned beverages have been commercially available by vending machines or the like. However, since the canned beverages are subjected to high temperature sterilization, there is a tendency that the flavor is substantially deteriorated, a so-called watery feeling is given, and the original flavor of the tea is lost.
Moreover, although various types of teas have been known as above, every type has its own flavor, and thus there is barely known teas liked by everyone, and teas have been selected by everyone's taste.